Speaker
Description
Terahertz (THz = 1012 Hz) spectroscopy is a promising analytical technique for non-destructive, highly accurate investigation. Since THz time- domain spectroscopy measures both amplitude and phase of transmission through materials, which can be used to extract the spectral shape of the conductivity spectrum, and THz pulses can act as ultrafast probes of intraband excitations of materials, it allows the determination of the complex permittivity of materials. THz-TDS is a contact-free probe of electrical conductivity with subpicosecond time resolution, and it has proven especially useful for studying emerging materials such as graphene, perovskites, and 2D semiconductors. However, despite its advantages, relatively long-wavelength and weak light-matter interaction limit the potential of these techniques to measure physical phenomena occurring within small areas and molecules, where many physical properties have been discovered. In this talk, we introduce recent research results with THz near-field spectroscopy for various research fields; mapping and visualization of electrical properties of graphene and 2D materials[1-3]. This method has the potential to be the basis for studies of charge distribution in space, which has been challenging to observe in a conventional way.
References
- Heo, C. et al. Identifying Fibrillization State of Aβ Protein via Near-Field THz Conductance Measurement. Acs Nano 14, 6548–6558 (2020).
- Seo, C. & Kim, T.-T. Terahertz near-field spectroscopy for various applications. J Korean Phys Soc 81 549-561 (2022).
3.Ha, T. et al. Subwavelength Terahertz Resonance Imaging (STRING) for Molecular Fingerprinting. Nano Lett 22, 10200–10207 (2022).
| Keywords | THz near-field spectroscopy, Ultrafast dynamics, Non-contact carrier dynamics |
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